1. False
2. True
3. True
4. False
5. True.
6. False.
7. True.
8. False.
9. False.
10. True.
11. False.
<h3><u>Explanation</u>:</h3>
A wave is a disturbance in a medium which can propagate through a medium. But the net displacement of the medium remains zero.
The spreading of the wave from a slit or hole is proved through the double slit experiment showing interference between the two waves. So they do spread by passing through a hole.
A longitudinal wave is what is seen when a stone is thrown into a pond. The ripples created are the compression points and the areas between the two ripple is called the rarefaction point.
Amplitude is defined as the maximum displacement of a particle in wave from its mean position. So its not distance between two compression points.
2nd law of reflection states that the angle of incidence is equal to angle of reflection.
An electromagnetic wave doesn't need a matter to get transferred. Its the electric field and magnetic field vibrating at same interval but in 90°to each other.
Mechanical wave needs matter to transfer energy. So it cannot travel through space.
Decibel is the unit of intensity of sound. Unit of frequency is hertz or cps.
Answer:
2000pound
Explanation:
Manganese metal is produced from the manganese(III) oxide, Mn2O3, which is found in manganite, a manganese ore. The manganese is reduced from its +3 oxidation state in Mn2O3 to the zero oxidation state of the uncharged metal by reacting the Mn2O3 with a reducing agent such as aluminum or carbon. How many pounds of manganese are in 1.261 tons of Mn2O3? (1 ton = 2000 pounds)
About 40 different substances called organophosphorus compounds are registered in the United States as insecticides. They are considered less damaging to the environment than some other insecticides because they breakdown relatively rapidly in the environment. The first of these organophosphorus insecticides to be produced was tetraethyl pyrophosphate, TEPP, which is 33.11% carbon, 6.95% hydrogen, 38.59% oxygen, and 21.35% phosphorus. It has a molecular mass of 290.190.
Energy conservation is the effort made to reduce the consumption of energy by using less of an energy service. This can be achieved either by using energy more efficiently or by reducing the amount of service used. Energy conservation is a part of the concept of Eco-sufficiency
Answer:
- 40.66
- 9.91
Explanation:
For the first question:
Our theoretical compound is MR₂
1 mol of MR₂ contains 1 mol of M and 2 moles of R
Let's find out the molar mass:
9.45 g/mol + 18.12 g/mol . 2 = 45.69 g/mol
We can solve this, by an easy rule of three:
1 mol of MR₂ weighs 45.69 grams
Then, 0.89 moles may weigh 40.66 g
For the second question:
Our theoretical compound is D₂G
Let's determine the molar mass:
11.45 g/mol . 2 + 44.57 g/mol = 67.47 g/mol
1 mol of anything contains 6.02×10²³ molecules. By this definition we can say that 6.02×10²³ molecules weigh 67.47 grams. Let's solve by the rule of three:
6.02×10²³ molecules weigh 67.47 g
8.84×10²² molecules may weigh (8.84×10²² . 67.47 ) / 6.02×10²³ = 9.91 g
